Based on the data of A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2007 to 2016， this paper examines the impact of stock liquidity on technological innovation from the perspective of enterprise life cycle. The study finds that stock liquidity significantly promotes technological innovation of enterprises and shows certain structural innovation dynamics. After dividing the life cycle of enterprise， it is found that enterprises in the initial stage and mature stage are more likely to exhibit significant innovation-driven effects under the stimulation of high stock liquidity. Further mechanism research reveals that the stock liquidity of start-up enterprises can improve the investment level of enterprises and increase the innovation output. However， there is also evidence showing that the stock liquidity of mature enterprises has aggravated the short-sighted tendency of enterprises and is not conducive to the effective conversion of long-term capital gains. The research conclusions help to strengthen the promotion mechanism of stock liquidity to technological innovation and improve the efficiency of patent output.